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This study showed that a polylactide (PLA)-based composite filled with nanostructured hydroxyapatite (HAp) and a natural extract from the rhizome of Curcuma longa L. could provide an alternative to commonly used fossil-based plasticsfor food packaging. The incorporation of HAp into the PLA matrix had a positive effect on improving selected properties of the composites; the beneficial effect could be enhanced by introducing a green modifier in the form of an extract. Prior to the fabrication of the composite, the filler was characterized in terms of morphology and composition, and the composite was then fully characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman and Fourier transform infrared spectroscopy (FT-IR), and the mechanical, thermal, thermomechanical, and optical properties were investigated. The proposed material exhibits antioxidant properties against DPPH radicals and antibacterial performance against Escherichia coli (E. coli). The results showed that the nanocomposite has the highest antioxidant and antibacterial properties for 10 wt% HAp with an average diameter of rod-shaped structures below 100 nm. In addition, the introduction of turmeric extract had a positive effect on the tensile strength of the nanocomposites containing 1 and 5% HAp. As the resulting material adsorbs light in a specific wavelength range, it can be used in the medical sector, food-packaging, or coatings. [ABSTRACT FROM AUTHOR]

Antioxidants play an important role in the prevention of oxidative stress and have been widely used in medicine and healthcare. However, natural antioxidants have several limitations such as low stability, difficult long-term storage, and high cost of large-scale production. Along with significant advances in nanotechnology, nanomaterials have emerged as a promising solution to improve the limitations of natural antioxidants because of their high stability, easy storage, time effectiveness, and low cost. Among various types of nanomaterials exhibiting antioxidant activity, metal-based nanoantioxidants show excellent reactivity because of the presence of an unpaired electron in their atomic structure. In this review, we summarize some novel metal-based nanoantioxidants and classify them into two main categories, namely chain-breaking and preventive antioxidant nanomaterials. In addition, the applications of antioxidant nanomaterials in medicine and healthcare are also discussed. This review provides a deeper understanding of the mechanisms of metal-based nanoantioxidants and a guideline for using these nanomaterials in medicine and healthcare.

One of the bacteria that is frequently found on uncooked poultry meat is Escherichia coli (E. coli), which commonly results in food poisoning in customers. Therefore, this work was conducted to assess the prevalence and antibiotic susceptibility of E. coli recovered from raw chicken meat in the retail markets of Vinh Long Province. The findings revealed that the E. coli concentration in raw chicken meat at retail markets exceeds the specified standards for fresh meat. A total of forty-nine E. coli strains were obtained from retail chicken samples. On the basis of morphological and biochemical characteristics, 16S rRNA gene sequencing, and phylogenetic analysis, the 3 bacterial strains EP4_12, ETB_38, and EBM_45 were determined to be E. coli. The results of antibiotic susceptibility testing demonstrated that the isolated E. coli strains were susceptible to ampicillin-sulbactam, sulfamethoxazole-trimethoprim, and ceftazidime at rates of 84%, 47%, and 41%, respectively. In contrast, these bacteria were resistant to ampicillin, ciprofloxacin, amoxicillin, doxycycline, levofloxacin, streptomycin, and tetracycline at percentages of 82%, 73%, 69%, 65%, 49%, 49%, and 55%, respectively. Notably, 94% of the bacterial isolates identified in this study were multiresistant to many antibiotics (multiresistant to 3 to 10 antibiotics), of which multiresistant to six antibiotics accounted for the highest percentage (20%). Moreover, the findings also revealed that E. coli isolates were frequently exposed to antibiotics with a multiple antibiotic resistance (MAR) index > 0.2. Consequently, it is important to manage the spread of antibiotic-resistant E. coli in fresh chicken retail markets to protect consumer health.

Antibiotic resistance and the transmission of resistance genes among bacteria in aquaculture are attracting world attention. The investigation was conducted to evaluate the antibiotic susceptibility of Aeromonas schubertii, which causes intensively cultured internal white spot disease in snakehead from An Giang province of the Mekong Delta. The findings isolated 29 bacterial strains from the kidney, spleen, and liver of diseased snakehead fish. Based on the morphological, biochemical, and 16S rRNA gene sequencing results, two strains of As9 and As11 showed a similarity of 98.71 % and 97.07 % to A. schubertii strains ZL-1 and GZ210812, respectively. The disc diffusion method was used to conduct antibiograms of the strains for 12 antibiotics. The research indicated that the bacteria were susceptible to the antibiotics ceftazidime, cefalexin, and doxycycline at rates of 86 %, 59 %, and 55 %, respectively. Meanwhile, bacteria were highly resistant to amoxicillin (93 %), flumequine (83 %), ciprofloxacin (76 %), rifampicin (66 %), erythromycin (62 %), colistin (59 %), florfenicol (59 %), and novobiocin (41 %). Interestingly, 100 % of the bacterial strains in the study demonstrated a multidrug-resistant phenotype, resistant to at least two antibiotics or more.

The COVID-19 global pandemic has prompted governments to resort to or allow quasi-formal means to provide basic goods and services to communities that were forced into quarantine. We analyze how grassroots self-help strategies interact with the adaptation mechanisms of formal governance under crisis conditions. Drawing on empirical insights in Manila (Philippines) and Hanoi (Vietnam), we examine the practices that have enabled street vendors in the two metropolises to earn a living and to provide needed services to city residents. We explain how some lessons on co-production practices might inform post-pandemic recovery strategies and future policy-making processes in global South cities. [ABSTRACT FROM AUTHOR]

Abstract Vibrio parahaemolyticus is a significant causal agent of acute hepatopancreatic necrosis disease (AHPND), with huge production losses of white leg shrimp, Litopenaeus vannamei, cultivated globally, including aquaculture farms in the Mekong Delta of Vietnam. Controlling this disease is critical because of the worldwide expansion of antimicrobial‐resistant V. parahaemolyticus isolates. The purpose of this study was to determine the frequency of multi‐antibiotic resistance (MAR) in V. parahaemolyticus isolated from AHPND white leg shrimp extensively cultivated in Bac Lieu Province (Mekong Delta). Based on biochemical tests and toxR‐PCR positive detections, 34 V. parahaemolyticus isolates were identified. Antibiotic susceptibility examination revealed that most of the isolates were phenotypically multidrug resistant, including resistance to ceftazidime (100%) and amoxicillin (97.06%), followed by colistin (74%) and erythromycin (65%). These isolates were highly sensitive to doxycycline (94%), followed by florfenicol (74%) and flumequine (71%). There were 27 distinct MAR phenotypes detected among 34 isolates, with 14.71% of the isolates exhibiting the antibiotic profile AMO‐CEF‐CEP‐COL‐ERY, followed by 11.76% for each of the profiles AMO‐CEP‐TET‐COL and AMO–CEP–COL. In particular, 25 isolates (75%) were resistant to at least 5 (of the 12) antibiotics tested. A hierarchical clustering analysis of antibiotic‐resistant V. parahaemolyticus isolates indicated cross‐transmission across farms and its ability to survive in aquatic environments for extended periods (over 3 months). Our findings support the hypothesis that the variety of MARPs in V. parahaemolyticus is the result of human activities. Environmentally friendly therapy strategies should be used for the prophylaxis and treatment of V. parahaemolyticus infection.

The diversity in structure and herbicidal properties detected in natural phytotoxic compounds could bring about advantages for development bio-herbicides. The present study was carried out search for potential weed inhibitors from the parts of Mimosa pigra L. The ethyl acetate (EtOAc) extract of leaf of M. pigra showed inhibitory activity during the time that Echinochloa crus-galli (barnyardgrass) germinates and grows, which is greater than that of other extracts. From this active extract, potent growth inhibitors were isolated and identified by column chromatography (CC), gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (1H and 13C NMR). The six compounds were purified in this study namely: lupeol (C1, 13.2 mg), stigmastane-3,6-dione (C2, 14.7 mg), quercetin (C3, 20.2 mg), chrysoeriol (C4, 28 mg), methyl gallate (C5, 21.5 mg) and daucosterol (C6, 16.0 mg). The C2 (quercetin) compound completely inhibited the emergency, shoot height and root length of E. crus-galli at 1 mg/mL concentration (IC50 shoot height = 0.56 mg/mL). This was also the first study to report the isolation and allelopathic activity of lupeol, chrysoeriol and daucosterol from M. pigra leaf. Findings of this study highlighted that quercetin from M. pigra may become bio-herbicide to control barnyard grass and other grass weeds for the development of safe agriculture.